/*******************************************************************************
  Main Source File

  Company:
    Microchip Technology Inc.

  File Name:
    main.c

  Summary:
    This file contains the "main" function for a project.

  Description:
    This file contains the "main" function for a project.  The
    "main" function calls the "SYS_Initialize" function to initialize the state
    machines of all modules in the system
 *******************************************************************************/

/*******************************************************************************
* Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries.
*
* Subject to your compliance with these terms, you may use Microchip software
* and any derivatives exclusively with Microchip products. It is your
* responsibility to comply with third party license terms applicable to your
* use of third party software (including open source software) that may
* accompany Microchip software.
*
* THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS". NO WARRANTIES, WHETHER
* EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE, INCLUDING ANY IMPLIED
* WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY, AND FITNESS FOR A
* PARTICULAR PURPOSE.
*
* IN NO EVENT WILL MICROCHIP BE LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE,
* INCIDENTAL OR CONSEQUENTIAL LOSS, DAMAGE, COST OR EXPENSE OF ANY KIND
* WHATSOEVER RELATED TO THE SOFTWARE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS
* BEEN ADVISED OF THE POSSIBILITY OR THE DAMAGES ARE FORESEEABLE. TO THE
* FULLEST EXTENT ALLOWED BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS IN
* ANY WAY RELATED TO THIS SOFTWARE WILL NOT EXCEED THE AMOUNT OF FEES, IF ANY,
* THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR THIS SOFTWARE.
*******************************************************************************/


// *****************************************************************************
// *****************************************************************************
// Section: Included Files
// *****************************************************************************
// *****************************************************************************

#include <stddef.h>                     // Defines NULL
#include <stdbool.h>                    // Defines true
#include <stdlib.h>                     // Defines EXIT_FAILURE
#include "definitions.h"                // SYS function prototypes
#include <string.h>

/*
 * Protocol:
 * Master:     [WR_CMD ADDR1 ADDR0 DATA0 DATA1 .. DATAN] ... ... ... ... ... ... [RD_CMD ADDR1 ADDR0] [DUMMY DUMMY .. DUMMY]
 * Slave:      [DUMMY  DUMMY DUMMY DUMMY DUMMY .. DUMMY] ... ... ... ... ... ... [DUMMY  DUMMY DUMMY] [DATA0 DATA1 .. DATAN]
 * BUSY PIN:    ----------------------------------------------------------------
 * ____________|                                                                |____________________________________________
 *
 * WR_CMD = 0x02
 * RD_CMD = 0x03
 * BUSY   = 0x01
 * READY  = 0x00
 */

typedef enum
{
    APP_STATE_INITIALIZE,
    APP_STATE_READ,
    APP_STATE_WRITE,
    APP_STATE_IDLE,

} APP_STATES;

/* Commands */
#define APP_CMD_WRITE                       0x02
#define APP_CMD_READ                        0x03

#define APP_MEM_BUFFER_SIZE                 512
#define APP_RX_BUFFER_SIZE                  256
#define APP_TX_BUFFER_SIZE                  256

#define LED_On()                            LED_Clear()
#define LED_Off()                           LED_Set()

typedef struct
{
    uint8_t busy        :1;
    uint8_t reserved    :7;
}STATUS;

typedef struct
{
    volatile APP_STATES          state;
    volatile STATUS              status;
    volatile uint8_t             nBytesRead;
    volatile uint8_t             nBytesToWrite;
    volatile uint8_t             nBytesReadRequest;
    volatile uint16_t            memAddr;
}APP_DATA;

APP_DATA appData;

uint8_t APP_MemoryBuffer[APP_MEM_BUFFER_SIZE] =
{
    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
    0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f,
    0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f,
    0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f,
    0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f,
    0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f,
    0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f,
    0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f,
    0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f,
    0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f,
    0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf,
    0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7,0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf,
    0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xcb,0xcc,0xcd,0xce,0xcf,
    0xd0,0xd1,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,0xdb,0xdc,0xdd,0xde,0xdf,
    0xe0,0xe1,0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,0xeb,0xec,0xed,0xee,0xef,
    0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff,

    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
    0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f,
    0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f,
    0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f,
    0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f,
    0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f,
    0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f,
    0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f,
    0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f,
    0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f,
    0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf,
    0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7,0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf,
    0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xcb,0xcc,0xcd,0xce,0xcf,
    0xd0,0xd1,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,0xdb,0xdc,0xdd,0xde,0xdf,
    0xe0,0xe1,0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,0xeb,0xec,0xed,0xee,0xef,
    0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
};

uint8_t APP_RxData[APP_RX_BUFFER_SIZE];
uint8_t APP_TxData[APP_TX_BUFFER_SIZE];

void delay(uint32_t count)
{
    uint32_t i;

    // 1 loop roughly provides 1us delay at 32MHz CPU frequency
    for (i = 0; i < count; i++)
    {
        asm("NOP");asm("NOP");asm("NOP");asm("NOP");asm("NOP");asm("NOP");
        asm("NOP");asm("NOP");asm("NOP");asm("NOP");asm("NOP");asm("NOP");
        asm("NOP");asm("NOP");asm("NOP");asm("NOP");asm("NOP");asm("NOP");
        asm("NOP");asm("NOP");asm("NOP");asm("NOP");asm("NOP");asm("NOP");
    }
}

void SPIEventHandler(uintptr_t context )
{
    if (SERCOM6_SPI_ErrorGet() == SPI_SLAVE_ERROR_NONE)
    {
        appData.nBytesRead = SERCOM6_SPI_Read(APP_RxData, SERCOM6_SPI_ReadCountGet());

        switch(APP_RxData[0])
        {
            case APP_CMD_WRITE:
                if (appData.status.busy == 0)
                {
                    appData.status.busy = 1;
                    appData.memAddr = ((APP_RxData[1] << 8) | (APP_RxData[2]));
                    appData.nBytesToWrite = (appData.nBytesRead - 3);
                    appData.state = APP_STATE_WRITE;
                }
                break;

            case APP_CMD_READ:

                appData.memAddr = ((APP_RxData[1] << 8) | (APP_RxData[2]));
                appData.nBytesReadRequest = APP_RxData[3];

                if ((appData.memAddr + appData.nBytesReadRequest) <= APP_TX_BUFFER_SIZE)
                {
                    memcpy(APP_TxData, &APP_MemoryBuffer[appData.memAddr], appData.nBytesReadRequest);
                    SERCOM6_SPI_Write(APP_TxData, appData.nBytesReadRequest);
                }
                break;
        }

        if (appData.status.busy == 0)
        {
            /* Indicate to SPI Master that slave is ready for data transfer */
            SERCOM6_SPI_Ready();
        }
    }
}

int main ( void )
{
    /* Initialize all modules */
    SYS_Initialize ( NULL );

    appData.state = APP_STATE_INITIALIZE;

    while(1)
    {
        /* Check the application's current state. */
        switch (appData.state)
        {
            case APP_STATE_INITIALIZE:

                SERCOM6_SPI_CallbackRegister(SPIEventHandler, (uintptr_t) 0);

                /* Wait for instructions from SPI master */
                appData.state = APP_STATE_IDLE;

                break;

            case APP_STATE_WRITE:

                /* Adding delay to simulate busy condition */
                delay(1000);

                /* Copy received data into Application memory buffer */
                if ((appData.memAddr + appData.nBytesToWrite) <= APP_MEM_BUFFER_SIZE)
                {
                    memcpy(&APP_MemoryBuffer[appData.memAddr], &APP_RxData[3], appData.nBytesToWrite);
                }

                appData.status.busy = 0;

                appData.state = APP_STATE_IDLE;

                /* Indicate to SPI Master that slave is ready for data transfer */
                SERCOM6_SPI_Ready();

                break;

            case APP_STATE_IDLE:
                break;

            default:
                break;
        }
    }
}

/*******************************************************************************
 End of File
*/

